A group of domestic users believe that Coc Coc, a Vietnamese browser, has been quietly storing http cookies recording users’ history of logging in on Facebook and sending the information to another website.

Coc Coc administration has denied the accusation.

The criticism was made on April 15 by a member of the Vietnam SEM community (Search Engine Marketing) on Facebook. He said the information has been sent to https://spell.itim.vn, a website owned by Coc Coc Company Ltd, the firm that manages Coc Coc browser.

Soon after the content was posted, it received nearly 2,000 likes and 800 shares, plus comments showing concern among users, especially those who use Coc Coc as their main web browser.

More than 20 million Vietnamese use Coc Coc.

Cookies are data created to store information, including accounts and log-in passwords on a browser, making subsequent access faster. In other words, anyone who owns cookies can log in to a saved Facebook account without having to enter username or password.

Hieu Phan, head of the Coc Coc browser development team, explained that to serve the spellcheck feature, Coc Coc has to send what users put into text fields on the server.

"The server will check and return the hint result back to the browser. All postings are anonymous. Coc Coc does not know exactly who sent the data. These data are stored temporarily to fix errors and improve data quality,” he explained.

“This is a normal design for any online service," said Hieu Phan.

The Coc Coc representative affirmed that the feature does not work in the box for entering user’s passwords.

"So, it must not happen that user’s passwords are sent to Coc Coc's server," Hieu said.

Also according to Hieu, all of this data is encrypted so the user's data is kept secret.

Elaborating on the spellcheck feature, Hieu Phan said the feature helps users increase the efficiency of typing text on the network environment.

When user types comments on Facebook or types text on any online text editor window in Vietnamese language without accents, Coc Coc will automatically fill in Vietnamese characters with accent marks at the high accuracy rate of nearly 100 percent.

The feature saves around 20 percent of time on typing text. It also discovers spelling errors and gives suggestions.

Nam Le, an admin of SEM Vietnam, said that the data Coc Coc uploads to the server is not encrypted.

Hao Tran, a security expert on banking, said it is unclear if the information uploaded to server is encrypted, and even if it is encrypted, no one is sure if the receiver, or Coc Coc’s server, can decrypt the information.